Below is CM Parameter details. What need to be adjusted or improved?
System
+-----------------------+-----------+-----------+-----------+-----------+
| Receive Power Level | 8.4 dBmV | 8.3 dBmV | 7.9 dBmV | 6.7 dBmV |
+-----------------------+-----------+-----------+-----------+-----------+
| Signal to Noise Ratio | 34.6 dB | 34.9 dB | 35.4 dB | 35.1 dB |
+-----------------------+-----------+-----------+-----------+-----------+
| Transmit Power Level | 38.8 dBmV | 38.8 dBmV | 39.8 dBmV | 42.0 dBmV |
+-----------------------+-----------+-----------+-----------+-----------+
Signal
Downstream Channel
The data shown in the table below provides information about the signal coming
from the network to your cable modem.
+-----------------------+------------+------------+------------+------------+
| Channel ID | 1 | 2 | 3 | 4 |
+-----------------------+------------+------------+------------+------------+
| Downstream Frequency | 330.00 Mhz | 338.00 Mhz | 346.00 Mhz | 354.00 Mhz |
+-----------------------+------------+------------+------------+------------+
| Modulation | 256QAM | 256QAM | 256QAM | 256QAM |
+-----------------------+------------+------------+------------+------------+
| Power Level | 8.3 dBmV | 8.2 dBmV | 7.7 dBmV | 6.6 dBmV |
+-----------------------+------------+------------+------------+------------+
| Signal to Noise Ratio | 34.6 dB | 34.9 dB | 35.4 dB | 35.1 dB |
+-----------------------+------------+------------+------------+------------+
Upstream Channel
The data shown in the table below provides information about the signal being
transmitted to the network from your cable modem.
+--------------------+------------+------------+------------+------------+
| Channel ID | 2 | 1 | 3 | 4 |
+--------------------+------------+------------+------------+------------+
| Upstream Frequency | 43.90 Mhz | 37.30 Mhz | 50.30 Mhz | 56.70 Mhz |
+--------------------+------------+------------+------------+------------+
| Modulation | 64QAM | 64QAM | 64QAM | 64QAM |
+--------------------+------------+------------+------------+------------+
| Bit Rate | 30720 Kbps | 30720 Kbps | 30720 Kbps | 30720 Kbps |
+--------------------+------------+------------+------------+------------+
| Power Level | 38.8 dBmV | 38.8 dBmV | 39.8 dBmV | 42.0 dBmV |
+--------------------+------------+------------+------------+------------+
If this is a real HFC network, then your values are excellent. This is what you normally get when you connect a single CM "back-to-back" to CMTS.
I highly doubt that there is something "excellent". Based on customer complaints received, unstable Internet connection and ISP's inability to provide speed in accordance with the contract.
Well ... there are lots of other variables in the system with possible negative impact on stability of the service. You posted only subset of them (apparently those reported by CM). I said that these values are excellent (which are ... based on my previous experience). What about upstream C/N, MER? T3/T4 touts? DS/US FEC counters? Etc...
Actually, the upstream values look pretty low to me. While it may certainly work, it may not be transmitting high enough over the noise floor, and hence you may have packet loss issues. If it were me I would put a dc9 on the leg feeding the modem that would put the forward at -1 or so and the reverse at 48-50 dB. But it all depends on the noise floor and the SNR of the plant you are connected to.